Resolve #3420570 "Misspellings in schema"

Closes #3420570

core/lib/Drupal/Core/Entity/Query/Sql/QueryAggregate.php

@@ -95,7 +95,7 @@ protected function compileAggregate() {
   }
 
   /**
-   * Adds the groupby values to the actual query.
+   * Adds the group by values to the actual query.
    *
    * @return $this
    *   Returns the called object.